1. Field of the Invention
The present invention relates to a blood vessel detecting device for detecting blood vessels around tissue, in general, which is to be resected, such as an affected portion of mucosal tissue within the body cavity.
2. Description of the Related Art
In recent years, Endoscopic Mucosal Resection (EMR) has attracted attention as a standard medical treatment for early mucosal cancer, and the clinical usefulness thereof has been well known.
In normal polypectomy, a bulging affected portion bulging therearound is resected using a high-frequency snare. On the other hand, in a case of non-bulging affected portion generally flat therearound, known resection methods include: a method wherein a tumor is caused to swell by injecting a physiological salt solution to the submucous membrane, and the tumor thus swollen is resected by a high-frequency snare; and a method wherein the affected portion is resected by the high-frequency snare while pulling up the affected portion with holding forceps using 2-channel scope; and the like.
Note that other known methods include: a method wherein the affected portion is resected by a high-frequency snare while suctioning the affected portion using a silicone tube including an endoscope and the snare inserted therethrough, (EMR tube method); a method wherein the affected portion is resected by a high-frequency snare integrally included at the tip of a transparent cap mounted at the tip of a scope while suctioning the affected portion using the transparent cap (EMRC method), a method wherein tissue around the affected portion is incised so as to resect the affected portion using an IT knife (needle knife including a ceramic chip on the tip thereof) (IT knife method).
On the other hand, in general diagnosis, blood vessels can be diagnosed by observing B-mode tomographic images or Doppler images obtained in ordinary ultrasonic endoscope diagnosis. In this case, there is the need to press an ultrasonic transducer into contact with the precise portion containing a mucous membrane which is to be resected, during transmission/reception of ultrasonic waves. Accordingly, in general, a method wherein the ultrasonic transducer is covered with a balloon filled with water is employed.
Conventionally, as another method for detecting blood vessels and aneurysms occurring in the blood vessel, a method is known wherein turbulent sound occurring in the blood vessel, i.e., Korotokov sound, is detected. The measurement of blood pressure is known as a specific application example. Description will be made regarding the technique with reference to conventional arrangements.
A sphygmomanometer disclosed in Japanese Unexamined Patent Application Publication No. 2001-309894 employs a mechanism for detecting the aforementioned-Korotokov sound.
With the aforementioned conventional sphygmomanometer, a cuff is wrapped around the upper arm of the subject, and the arteries are constricted by pressure in order to detect the Korotokov sound (K-sound). The conventional sphygmomanometer comprises a K-sound sensor for detecting the Korotokov sound (K-sound), a pressure sensor for detecting the pressure within the upper arm, a peripheral-vein pulse pressure sensor, a pressure-sensor amplifier, and the like.
In the measurement with the sphygmomanometer, the peripheral-vein pulse pressure sensor is attached onto the portion peripheral to the cuff-wrapped portion, subsequently, the peripheral-vein pulse pressure (relative value) is measured by the peripheral-vein pulse pressure sensor over the pressure of the cuff in the step of slow pressure reduction following pressure application, as well as measuring the pressure of the cuff. From the measurement results, the peak value of the peripheral-vein pulse pressure (relative value) is obtained, and the pressure of the cuff corresponding to the aforementioned peak value is determined to be the maximum peripheral-vein pulse pressure.
On the other hand, in recent research, measurement results, which suggest that cardiac murmur can be detected in a patient affected by aortopathy due to turbulence within the blood vessels thereof, have been reported as described in the document (Kanai et al. “Measurement of spatial distribution of great velocity components of the myocardium and change in thickness of the local portion thereof”, J. Med. Ultrasonics, Vol. 29, No. 4, (2002) S235).
As described above, it is known that turbulence causes turbulent sound in the blood vessels, and accordingly, the blood pressure and presence or absence of an aneurysm can be detected by detecting the sound, i.e., the Korotokov sound.